1/* 2 * OpenVPN -- An application to securely tunnel IP networks 3 * over a single TCP/UDP port, with support for SSL/TLS-based 4 * session authentication and key exchange, 5 * packet encryption, packet authentication, and 6 * packet compression. 7 * 8 * Copyright (C) 2002-2011 OpenVPN Technologies, Inc. <sales@openvpn.net> 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License version 2 12 * as published by the Free Software Foundation. 13 * 14 * This program is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 * GNU General Public License for more details. 18 * 19 * You should have received a copy of the GNU General Public License 20 * along with this program (see the file COPYING included with this 21 * distribution); if not, write to the Free Software Foundation, Inc., 22 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 23 */ 24 25/* 26 * Maintain usage stats in a memory-mapped file 27 */ 28 29#ifdef HAVE_CONFIG_H 30#include "config.h" 31#elif defined(_MSC_VER) 32#include "config-msvc.h" 33#endif 34 35#include "syshead.h" 36 37#if defined(ENABLE_MEMSTATS) 38 39#include <sys/mman.h> 40 41#include "error.h" 42#include "misc.h" 43#include "mstats.h" 44 45#include "memdbg.h" 46 47volatile struct mmap_stats *mmap_stats = NULL; /* GLOBAL */ 48static char mmap_fn[128]; 49 50void 51mstats_open(const char *fn) 52{ 53 void *data; 54 ssize_t stat; 55 int fd; 56 struct mmap_stats ms; 57 58 if (mmap_stats) /* already called? */ 59 return; 60 61 /* verify that filename is not too long */ 62 if (strlen(fn) >= sizeof(mmap_fn)) 63 msg (M_FATAL, "mstats_open: filename too long"); 64 65 /* create file that will be memory mapped */ 66 fd = open (fn, O_CREAT | O_TRUNC | O_RDWR, S_IRUSR | S_IWUSR); 67 if (fd < 0) 68 { 69 msg (M_ERR, "mstats_open: cannot open: %s", fn); 70 return; 71 } 72 73 /* set the file to the correct size to contain a 74 struct mmap_stats, and zero it */ 75 CLEAR(ms); 76 ms.state = MSTATS_ACTIVE; 77 stat = write(fd, &ms, sizeof(ms)); 78 if (stat != sizeof(ms)) 79 { 80 msg (M_ERR, "mstats_open: write error: %s", fn); 81 close(fd); 82 return; 83 } 84 85 /* mmap the file */ 86 data = mmap(NULL, sizeof(struct mmap_stats), PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); 87 if (data == MAP_FAILED) 88 { 89 msg (M_ERR, "mstats_open: write error: %s", fn); 90 close(fd); 91 return; 92 } 93 94 /* close the fd (mmap now controls the file) */ 95 if (close(fd)) 96 { 97 msg (M_ERR, "mstats_open: close error: %s", fn); 98 } 99 100 /* save filename so we can delete it later */ 101 strcpy(mmap_fn, fn); 102 103 /* save a global pointer to memory-mapped region */ 104 mmap_stats = (struct mmap_stats *)data; 105 106 msg (M_INFO, "memstats data will be written to %s", fn); 107} 108 109void 110mstats_close(void) 111{ 112 if (mmap_stats) 113 { 114 mmap_stats->state = MSTATS_EXPIRED; 115 if (munmap((void *)mmap_stats, sizeof(struct mmap_stats))) 116 msg (M_WARN | M_ERRNO, "mstats_close: munmap error"); 117 platform_unlink(mmap_fn); 118 mmap_stats = NULL; 119 } 120} 121 122#endif 123